The somatotroph cells of the anterior pituitary gland produce growth hormone (GH).
GH deficiency in adults usually manifests as reduced physical performance and impaired psychological well-being. It results in alterations in the physiology of different systems of the body, manifesting as altered lipid metabolism, increased subcutaneous and visceral fat, decreased muscle mass, decreased bone density, low exercise performance, and reduced quality of life.

Cabergoline, an ergot derivative, is a long-acting dopamine agonist. It is usually better tolerated than Bromocriptine (BEC), and its efficacy profiles are somewhat superior to those of BEC. It offers the convenience of twice-a-week administration, with a usual starting dose of 0.25 mg biweekly to a maximum dose of 1 mg biweekly. Some studies have shown efficacy even with once-a-week dosing. Cabergoline appears to be more effective in lowering prolactin levels and restoring ovulation. Up to 70% of patients who do not respond to BEC respond to cabergoline.

In myasthenia gravis, repeated muscle contractions lead to reduced muscle strength. The opposite is however classically seen in the related disorder Lambert-Eaton syndrome. Lambert-Eaton myasthenic syndrome is seen in association with small cell lung cancer, and to a lesser extent breast and ovarian cancer. It may also occur independently as an autoimmune disorder. Lambert-Eaton myasthenic syndrome is caused by an antibody directed against pre-synaptic voltage gated calcium channel in the peripheral nervous system.

Peroneal nerve injury is also known as foot drop. The common peroneal nerve supplies the ankle and toe extensor muscle groups as well as sensation over the dorsum of the foot; thus, there is also loss of sensation in these cases.

Synacthen test interpretation:
– Basal Cortisol level should be greater than 180nmol/L
– 30min or 60min Cortisol should be greater than 420nmol/L (whatever the basal level)
– The increment should be at least 170nmol/L, apart from in severely ill patients where adrenal output is already maximal.
The patient’s results show that she has Acute Adrenal Insufficiency
The guidelines include the following recommendations for emergency treatment:
Administer hydrocortisone: Immediate bolus injection of 100 mg hydrocortisone intravenously or intramuscularly followed by continuous intravenous infusion of 200 mg hydrocortisone per 24 hours (alternatively, 50 mg hydrocortisone per intravenous or intramuscular injection every 6 h)
Rehydrate with rapid intravenous infusion of 1000 mL of isotonic saline infusion within the first hour, followed by further intravenous rehydration as required (usually 4-6 L in 24 h; monitor for fluid overload in case of renal impairment and elderly patients)
Contact an endocrinologist for urgent review of the patient, advice on further tapering of hydrocortisone, and investigation of the underlying cause of the disease, including the diagnosis of primary versus secondary adrenal insufficiency
Tapering of hydrocortisone can be started after clinical recovery guided by an endocrinologist; in patients with primary adrenal insufficiency, mineralocorticoid replacement must be initiated (starting dose 100 μg fludrocortisone once daily) as soon as the daily glucocorticoid dose is below 50 mg of hydrocortisone every 24 hours

This patient has polycystic ovarian syndrome (PCOS). Medical management of PCOS is aimed at the treatment of metabolic derangements, anovulation, hirsutism, and menstrual irregularity.
First-line medical therapy usually consists of an oral contraceptive to induce regular menses. The contraceptive not only inhibits ovarian androgen production but also increases sex hormone-binding globulin (SHBG) production. The American College of Obstetricians and Gynaecologists (ACOG) recommends the use of combination low-dose hormonal contraceptive agents for long-term management of menstrual dysfunction.
If symptoms such as hirsutism are not sufficiently alleviated, an androgen-blocking agent may be added. Pregnancy should be excluded before therapy with oral contraceptives or androgen-blocking agents are started.
First-line treatment for ovulation induction when fertility is desired is clomiphene citrate. Second-line strategies may be equally effective in infertile women with clomiphene citrate–resistant PCOS.

Ethylene glycol poisoning is the only poison listed that will cause dilation of the pupils whereas all the other listed conditions and poisons will present with small pupils other than in the case of Myotonic dystrophy wherein the patient will present with a cortical cataract.

RET (rearranged during transfection) is a receptor tyrosine kinase involved in the development of neural crest derived cell lineages, kidney, and male germ cells. Different human cancers, including papillary and medullary thyroid carcinomas, lung adenocarcinomas, and myeloproliferative disorders display gain-of-function mutations in RET.
In over 90% of cases, MEN2 syndromes are due to germline missense mutations of the RET gene.
Multiple endocrine neoplasias type 2 (MEN2) is an inherited disorder characterized by the development of medullary thyroid cancer (MTC), parathyroid tumours, and pheochromocytoma.

This patient is having a myasthenic crisis. Opinions vary as to whether plasmapheresis or intravenous immunoglobulins should be given first-line. Plasmapheresis usually works much faster, but is more costly due to equipment.
Myasthenia gravis is an autoimmune disorder resulting in insufficient functioning acetylcholine receptors. Antibodies to acetylcholine receptors are seen in 85-90% of cases. Myasthenia gravis is more common in women (2:1).

Downbeat nystagmus (DBN) suggests a lesion in the lower part of the medulla. Chiari Type I malformation usually presents with symptoms due to brain stem and lower cranial nerve dysfunction, which includes DBN.

This man has a small-cell lung cancer (SCLC) and associated Lambert-Eaton myasthenic syndrome – a well-recognized paraneoplastic manifestation of SCLC. This classically affects the proximal muscles, especially in the legs, causing difficulty in standing from a seated position and climbing stairs. In contrast to myasthenia gravis, eye involvement is uncommon. Treatment with steroids is often helpful, which explains his transient symptomatic improvement during treatment for his COPD exacerbation. Steroid myopathy does not fit as the symptoms started well before his course of prednisolone. Although the patient is mildly hypercalcaemic, this would not be sufficient to produce his presenting symptoms, although it does reinforce the suspicion of lung malignancy. Motor neurone disease would be unlikely in this context and would not improve with steroids. Myasthenia gravis could produce these symptoms, but in the context of a new lung mass is a less viable diagnosis.

This woman has a history that is suggestive of Guillain– Barré syndrome. This may be precipitated by Campylobacter, and her history of recent diarrhoeal illness is pointing towards that. Certain features point to a poor prognosis, including rapidity of onset, reduced vital capacity or respiratory failure, age >40 and reduced amplitude of compound muscle action potential. Her inability to perform spirometry and desaturating whilst lying flat are suggestive of impending respiratory muscle weakness. Review for consideration of ventilation is recommended. Further management of choice for Guillain-Barre syndrome is IV immunoglobulins. Steroids have no value in the treatment of the condition.

Patients who have autonomously functioning nodules should be treated definitely with radioactive iodine or surgery.
Na131 I treatment – In the United States and Europe, radioactive iodine is considered the treatment of choice for Toxic Nodular Goitre. Except for pregnancy, there are no absolute contraindications to radioiodine therapy.

Achondroplasia is the most common type of short-limb disproportionate dwarfism. A single gene mapped to the short arm of chromosome 4 (band 4p16.3) is responsible for achondroplasia and is transmitted as an autosomal dominant trait. All people with achondroplasia have a short stature.
Characteristic features of achondroplasia include an average-size trunk, short arms and legs with particularly short upper arms and thighs, limited range of motion at the elbows, and an enlarged head (macrocephaly) with a prominent forehead. Fingers are typically short and the ring finger and middle finger may diverge, giving the hand a three-pronged (trident) appearance. People with achondroplasia are generally of normal intelligence.
Examination of the infant after birth shows increased front-to-back head size. There may be signs of hydrocephalus. It may be diagnosed radiographically at birth, or becomes obvious within the first year with disparity between a large skull, normal trunk length and short limbs.

Elevated TSH (usually 4.5-10.0 mIU/L) with normal free T4 is considered mild or subclinical hypothyroidism.
Hypothyroidism commonly manifests as a slowing in physical and mental activity but may be asymptomatic. Symptoms and signs are often subtle and neither sensitive nor specific.
The following are symptoms of hypothyroidism:
– Fatigue, loss of energy, lethargy
– Weight gain
– Decreased appetite
– Cold intolerance
– Dry skin
– Hair loss
– Sleepiness
– Muscle pain, joint pain, weakness in the extremities
– Depression
– Emotional lability, mental impairment
– Forgetfulness, impaired memory, inability to concentrate
– Constipation
– Menstrual disturbances, impaired fertility
– Decreased perspiration
– Paraesthesia and nerve entrapment syndromes
– Blurred vision
– Decreased hearing
– Fullness in the throat, hoarseness
Physical signs of hypothyroidism include the following:
– Weight gain
– Slowed speech and movements
– Dry skin
– Jaundice
– Pallor
– Coarse, brittle, straw-like hair
– Loss of scalp hair, axillary hair, pubic hair, or a combination
– Dull facial expression
– Coarse facial features
– Periorbital puffiness
– Macroglossia
– Goitre (simple or nodular)
– Hoarseness
– Decreased systolic blood pressure and increased diastolic blood pressure
– Bradycardia
– Pericardial effusion
– Abdominal distention, ascites (uncommon)
– Hypothermia (only in severe hypothyroid states)
– Nonpitting oedema (myxoedema)
– Pitting oedema of lower extremities
– Hyporeflexia with delayed relaxation, ataxia, or both.

Motor neuron disease is a neurological condition of unknown cause which can present with both upper and lower motor neuron signs. It rarely presents before age 40 and various patterns of disease are recognised, including amyotrophic lateral sclerosis, progressive muscular atrophy and bulbar palsy.
Non-invasive ventilation (usually BIPAP) is used at night, with studies having shown a survival benefit of around 7 months. Riluzole prevents stimulation of glutamate receptors, used mainly in amyotrophic lateral sclerosis and has been shown to prolong life by about 3 months.

Bilateral median nerve dysfunction is suggestive of degenerative cervical myelopathy (DCM) rather than bilateral carpal tunnel syndrome. DCM should be suspected in elderly patients presenting with limb neurology. This patient’s twitches are probably fibrillations, a sign of lower motor neuron dysfunction.
Degenerative cervical myelopathy is associated with a delay in diagnosis. It is most commonly misdiagnosed as carpal tunnel syndrome. In one study, 43% of patients who underwent surgery for degenerative cervical myelopathy had been initially diagnosed with carpal tunnel syndrome.
Management of these patients should be by specialist spinal services (neurosurgery or orthopaedic spinal surgery). Decompressive surgery is the mainstay of treatment and has been shown to stop disease progression. Physiotherapy and analgesia do not replace surgical opinion, though they may be used alongside. Nerve root injections do not have a role in management.

Diabetes insipidus (DI) is defined as the passage of large volumes (>3 L/24 hr) of dilute urine (< 300 mOsm/kg). It has the following 2 major forms:
– Central (neurogenic, pituitary, or neurohypophyseal) DI, characterized by decreased secretion of antidiuretic hormone (ADH; also referred to as arginine vasopressin [AVP])
– Nephrogenic DI, characterized by decreased ability to concentrate urine because of resistance to ADH action in the kidney
This patient has the central type from metastases.
In patients with central DI, desmopressin is the drug of choice. It is a synthetic analogue of antidiuretic hormone (ADH). It is available in subcutaneous, IV, intranasal, and oral preparations. Generally, it can be administered 2-3 times per day. Patients may require hospitalization to establish fluid needs. Frequent electrolyte monitoring is recommended during the initial phase of treatment.

Oculomotor nerve palsy is an eye condition resulting from damage to the third cranial nerve or a branch thereof. A complete oculomotor nerve palsy will result in a characteristic down and out position in the affected eye. This is because the lateral rectus (innervated by the sixth cranial nerve) and superior oblique (innervated by the fourth cranial or trochlear nerve), is unantagonized by the paralyzed superior rectus, inferior rectus and inferior oblique. The affected individual will also have a ptosis, or drooping of the eyelid, and mydriasis (pupil dilation), not miosis.

Bicarbonate therapy is not indicated in mild and moderate forms of DKA because metabolic acidosis will correct with insulin therapy. The use of bicarbonate in severe DKA is controversial due to a lack of prospective randomized studies. It is thought that the administration of bicarbonate may actually result in peripheral hypoxemia, worsening of hypokalaemia, paradoxical central nervous system acidosis, cerebral oedema in children and young adults, and an increase in intracellular acidosis. Because severe acidosis is associated with worse clinical outcomes and can lead to impairment in sensorium and deterioration of myocardial contractility, bicarbonate therapy may be indicated if the pH is 6.9 or less.

Leaking of cerebrospinal fluid from the dura is the most likely explanation for post-lumbar puncture headaches. It is thought that ongoing leak of cerebrospinal fluid (CSF) through the puncture site causes ongoing CSF loss, leading to low pressure. A post-LP headache is typically frontal or occipital and occurs within three days. It is normally associated with worsening on standing and improvement when lying down. Treatment in severe cases includes an epidural blood patch, but most resolve on their own.

In restless leg syndrome (RLS), males and females are thought to be equally affected. RLS is a syndrome of spontaneous, continuous lower limb movements that may be associated with paraesthesia. It is extremely common, affecting between 2-10% of the general population and a family history may be present.

Treatment with fibrates, a widely used class of lipid-modifying agents, results in a substantial decrease in plasma triglycerides and is usually associated with a moderate decrease in LDL cholesterol and an increase in HDL cholesterol concentrations.
Evidence from studies is available to implicate 5 major mechanisms underlying the above-mentioned modulation of lipoprotein phenotypes by fibrates:
1. Induction of lipoprotein lipolysis.
2. Induction of hepatic fatty acid (FA) uptake and reduction of hepatic triglyceride production.
3. Increased removal of LDL particles. Fibrate treatment results in the formation of LDL with a higher affinity for the LDL receptor, which is thus catabolized more rapidly.
4. Reduction in neutral lipid (cholesteryl ester and triglyceride) exchange between VLDL and HDL may result from decreased plasma levels of TRL.
5. Increase in HDL production and stimulation of reverse cholesterol transport. Fibrates increase the production of apoA-I and apoA-II in the liver, which may contribute to the increase of plasma HDL concentrations and a more efficient reverse cholesterol transport.

Downbeat nystagmus (DBN) suggests a lesion in the lower part of the medulla. Arnold-Chiari malformation usually presents with symptoms due to brainstem and lower cranial nerve dysfunction such as DBN.

Exogenous thyroid hormone use has been associated with episodes of thyroid storm as well as thyrotoxic periodic paralysis.
It presents with marked proximal muscle weakness in both upper and lower limbs, hypokalaemia and signs of hyperthyroidism.
Hyperthyroidism generally presents with tachycardia, hypertension, hyperthermia, and cardiac arrhythmias

Laxatives and diuretics can result in electrolyte abnormalities.
Medical complications associated with laxatives include chronic diarrhoea which disrupts the normal stool electrolyte concentrations that then leads to serum electrolyte shifts; acutely, hypokalaemia is most typically seen. The large intestine suffers nerve damage from the chronic laxative use that renders it unable to function properly. The normal peristalsis and conduction are affected; the disorder is thought to be secondary to a degeneration of Auerbach’s Plexi. However, it does not cause muscle weakness.

Insulin tends to cause weight gain, not weight loss.
Metformin does not cause muscle weakness but can cause headaches.

Juvenile Onset Parkinson’s is an autosomal recessive condition that usually presents in late childhood to early adulthood, initially with gait disorders caused by lower limb dystonia that later develops to the more classical signs Parkinson’s.

Paget disease is a localized disorder of bone remodelling that typically begins with excessive bone resorption followed by an increase in bone formation. This osteoclastic over activity followed by compensatory osteoblastic activity leads to a structurally disorganized mosaic of bone (woven bone), which is mechanically weaker, larger, less compact, more vascular, and more susceptible to fracture than normal adult lamellar bone.
Approximately 70-90% of persons with Paget disease are asymptomatic; however, a minority of affected individuals experience various symptoms, including the following:
– Bone pain (the most common symptom)
– Secondary osteoarthritis (when Paget disease occurs around a joint)
– Bony deformity (most commonly bowing of an extremity)
– Excessive warmth (due to hypervascularity)
– Neurologic complications (caused by the compression of neural tissues)
Measurement of serum alkaline phosphatase—in some cases, bone-specific alkaline phosphatase (BSAP)—can be useful in the diagnosis of Paget disease. Elevated levels of urinary markers, including hydroxyproline, deoxypyridinoline, C-telopeptide, and N -telopeptide, may help identify patients with Paget disease.
Serum calcium and phosphate levels should be within the reference range in patients with Paget disease.

The given history suggests a small fibre painful peripheral sensory neuropathy, the most common cause of which is diabetes. Joint position sense and vibratory sensation are carried through large fibres, and therefore are not currently affected. Sensory nerves are affected more often than motor, so reflexes usually remain in tact.

Vitamin B12 deficiency causes impairment of joint position and vibratory sensation.

Chronic inflammatory demyelinating polyneuropathy (CIPD) causes a large fibre peripheral neuropathy with areflexia.

In syringomyelia there is impaired pain and temperature noted in the upper limbs.

Finally, with alcoholic polyneuropathy, all fibre types are affected (sensory and motor loss). It is usually gradual with long term alcohol abuse and may be accompanied by a nutritional deficiency. In addition, pain is a more dominant feature.

Several dipeptidyl peptidase-4 (DPP-4) inhibitors are in clinical development; these are orally active and increase levels of active glucagon-like peptide-1 (GLP-1), which in turn increases insulin secretion and reduces glucagon secretion, thereby lowering glucose levels.
Sitagliptin and vildagliptin both have a long duration of action, allowing once-daily administration. Both sitagliptin and vildagliptin are safe and tolerable with a low risk of hypoglycaemia. In drug-naïve subjects with type 2 diabetes, both sitagliptin and vildagliptin reduce A1C levels by ,1% as monotherapy.

This patient presents with a combination of akinetic rigid syndrome, cerebellar signs and the suggestion of autonomic features. This is most indicative of a diagnosis of multiple system atrophy.

Multiple system atrophy (MSA) is a rare neurodegenerative disorder characterized by autonomic dysfunction, tremors, slow movement, muscle rigidity, and postural instability (collectively known as parkinsonism) and ataxia.